The present invention relates generally to diagnostic assay systems and methods thereof that are capable of conducting and recording assays in a simple and reliable manner.
A wide variety of systems and approaches exist which allow the occurrence and recording of luminescent reactions, such as of the chemiluminescent, or fluorescent type for qualitative and quantitative results. One class of analytical instruments typically used in this field is referred to as luminometers. Luminometers conduct and record luminescent reactions generated, for instance, by a biological test fluid sample that contains a reagent of interest, such as an analyte, and a reagent in an assay element. Examples of these approaches include single-sample luminometers fitted with photographic multipliers; single-sample luminometers fitted with solid-state detectors; multiple sample luminometers; automatic luminometers with imaging systems based on CCD cameras; and photographic camera type luminometers. Some of the foregoing devices using photographic films of the conventional and self-developing type for recording luminescent activity are described in, for example, in U.S. Pat. Nos.: 4,863,689; 5,035,866; and, 5,188,965. Heretofore known prior art tends to be limited in a number of ways, such as being expensive due to the relatively expensive electronics required, training of personnel required because of their relatively complicated nature, and being relatively cumbersome in use and expensive in construction.
In addition, the prior art contains many devices that deliver a solution containing an analyte of interest to a testing solution for generating a luminescent read-out signal that indicates the presence of an analyte of interest. It is important in conducting these assays for the solution containing such an analyte to be delivered to a testing solution in a manner that enhances the reliability of the testing. One known testing device is commercially available from Biotrace, Inc., Plainsboro, N.J. that uses a pick-up device or swab having testing rings that swipe a surface to be tested. The ampoule includes a generally hollow tubular housing for slidably receiving the pickup device. The ampoule is transparent, and has an open end portion that is adapted to receive the sample pick-up, and a closed end portion that is transparent whereby luminescent activity can form a latent image on a recording film. A sealing membrane is located generally transversely to the ampoule housing to define a chamber or reservoir with the closed end portion to sealingly accommodate an assay fluid therein. The sealing membrane is made of a thin-walled metallic material that is impervious to fluid and ambient atmosphere. The sealing membrane is adapted to be punctured by the sample pick-up device when the latter is inserted by an operator therethrough. The assay fluid can be one that generates a chemiluminescent signal in response to a reagent, such as ATP (Adenosine Triphosphate) being present on the sampling rings. ATP is used as an indicator of the presence of organic debris, such as microorganisms. The sample pick-up device includes a handle, a stem, and a plurality of laterally extending sampling rings. The sampling rings are used to engage a surface to be tested for microorganisms. A user merely rubs the rings against a surface to be tested, for instance, a food preparation surface and inserts the sampling ring into and through the membrane, whereupon the rings are immersed into the assay fluid. If ATP is present, in significant amounts on the sampling rings, it will react with the reagent in the fluid and generate a luminescent read-out signal that is recordable on the film.
Despite the existence of a wide variety of known diagnostic luminescent type testing systems and approaches, however, it is, nevertheless, desired to improve upon the overall ease, versatility, and reliability of such systems and their testing procedures, as well as reduce overall costs associated with their construction and use.
In accordance with the present invention provision is made for an improved device for implementing chemiluminescent tests in a robust manner. Provision is made for a chemical implementation device comprising: a housing assembly including at least a pair of containers each of which is adapted to contain a fluid; a fluid impervious membrane sealing one of the pair of containers from the other of the pair of containers, thereby keeping fluids in each of the containers separate; and, a penetrating assembly mounted for movement in the housing assembly and being adapted to engage and penetrate the sealing membrane upon movement in response to a force being applied thereto for allowing fluid in the one container to mix with fluid in the other container under pressure; the housing assembly including at least a segment thereof that is transparent to a read-out signal generated in response to a reaction of the mixing fluids.
In an illustrated preferred embodiment, the sealing membrane includes a main body having at least one flap integral therewith and a weakened frangible portion of the membrane surrounding a peripheral portion of the flap such that the penetrating assembly can force separation of the flap from the body along the frangible portion to thereby facilitate flow of fluid from the one chamber to the other chamber.
In another illustrated preferred embodiment, the housing assembly includes two housing portions, each one of which defines a respective one of the chambers, wherein one of the two housing portions is removably coupled to the other portion for allowing separation and rejoining of the housing portions.
In still another illustrated preferred embodiment, the penetrating assembly includes a piston portion that is in sliding engagement with an internal wall of one of the chambers and is movable with the penetrating element for forcing fluid in the one chamber into the other chamber.
In yet still another illustrated embodiment, the piston portion has a frictional fit with the internal wall that is sufficient in magnitude to resist piston movement until application thereto of a reselected force.
In an illustrated and preferred embodiment of the present invention, a chemiluminescent test implementing device is provided that is a capable of storing testing solutions in separable chambers until implementation of a particular testing procedure is commenced. Included in the implementing device is a container comprising at least two adjoining chambers, each one of which is adapted to contain an appropriate solution. For sealingly separating these solutions prior to commencing a testing procedure, provision is made for a sealing assembly. When the testing is commenced the seal is opened by a device that penetrates the seal as well as induces in intimate or vortex-like mixing action for allowing the separated test fluids to be intimately mixed. Accordingly, an opportunity exists for a more robust chemiluminescent reaction occurring. A window at the bottom of the mixing chamber is in juxtaposed relationship to a film unit and allows for a chemiluminescent reaction to be recorded. Opening the sealing assembly and inducing the vortex-like mixing in the mixing chamber occurs responsive to penetration of the seal by a member that is advanced by forces transmitted thereto by a force-applying member. The force applying member can be activated such as when the operator closes a cover in a testing device. In addition, the container allows one of the chambers to be separated from the housing assembly to allow an operator to insert a sampling device, such as a swab containing microorganisms, into the fluid retained in the chamber. The chamber is then rejoined to the container in preparation of the seal being opened by the penetrating device upon application of the penetrating force, thereby allowing the fluids in both chambers to be mixed so as to be capable of generating a luminescent read-out signal recordable on an image recording medium. In a further illustrated embodiment, the penetrating device includes a piston which upon application of the penetrating force acts to force testing fluid under pressure from the one chamber to the mixing chamber under a vortex-like mixing action so as to better ensure the mixing of the solutions.